More than 120 new violations were found, including failures to maintain adequate ventilation and water-spraying equipment underground, which work together to suppress coal dust and minimize its inhalation by coal miners.

Excessive coal dust was cited as a major cause of the massive explosion that ripped through the Upper Big Branch coal mine in West Virginia in 2010, killing 29 coal miners.

Failure to control coal dust is also cited as the source of black lung, a deadly disease that strikes coal miners.

The September "impact inspection" followed reporting in July by NPR, the Center for Public Integrity and The Charleston Gazette, which found a dramatic increase in black lung cases in Appalachia and widespread failures in the system that's supposed to detect and control coal dust exposures. But the Mine Safety and Health Administration insists that the NPR, CPI and Gazette reports did not prompt the coal dust inspections.

MSHA has had a special inspection program focused on coal dust for several years, notes agency spokeswoman Amy Louviere. But monthly "impact inspections" began after the Upper Big Branch tragedy in 2010; the September blitz was the first to specifically target mines with persistent coal dust control problems.

"Due to the egregious nature of some of the recent dust-related violations our inspectors have been finding," Louviere says, "[Main] decided it was important to give special consideration to these compliance issues."

One of the coal mines singled out by MSHA inspectors was once owned by Massey Energy, the company that owned the Upper Big Branch mine. The Roundbottom Powellton Mine in Boone County, W.Va., is now owned by Alpha Natural Resources but is still managed by a former Massey official who supervised some of Massey's most troubled mines.

MSHA inspectors found 21 violations at Roundbottom Powellton, including "improperly ventilated areas" and dysfunctional water sprays that help control coal dust. Citations were also issued for excessive accumulations of coal dust.

Two other mines cited are owned by Robert Murray, the controversial owner of Murray Energy. Murray's Crandall Canyon coal mine in Utah experienced two collapses in 2007, killing nine miners and rescuers.

Murray, a persistent critic of government regulation, has been prominent in the presidential campaign of Republican Mitt Romney.

In August, he hosted a rally for Romney at one of his Ohio coal mines, which is not one of the mines cited recently by MSHA.

"You've got a great boss. He runs a great operation here," Romney told Murray employees, some of whom later complained that they were required to attend the event.

The rally appearance is now the subject of dueling Romney and President Obama campaign ads broadcast heavily in Ohio, a critical battleground state. Both Murray and Romney have accused the Obama administration of waging a "war on coal" with its regulation of coal mines and coal-fired powered plants.

Murray's New Future Mine in Illinois received eight citations for respirable dust issues. Five are considered "serious and substantial." His West Ridge mine in Utah was cited for six violations. Inspectors also issued four withdrawal orders requiring immediate evacuation of specific areas of the mine.

Coal mines were also targeted and cited in Pennsylvania, Virginia and Alabama.